1. Technical Field of the Invention
The present invention relates to a computer system and method for transferring data between multiple peer-level storage units and, in particular, to a computer system and method using an intelligent controller and storage area network for routing data between peer-level storage units.
2. Description of Related Art
Currently, one of the most significant design challenges for manufacturers of computer systems is the development of efficient storage management systems and procedures for routing data between different storage units. Storage management procedures generally include copying or moving data from a disk drive and then transferring the data to a tape drive for archival and backup purposes. The backup or archived data may be restored from the tape drive if, for example, the data on the disk drive is destroyed or a user wants to retrieve the archived data.
Referring to FIG. 1A, there is illustrated a conventional computer system 100 including a storage management scheme having two backup data paths 102 and 104. In describing the components associated with the first backup data path 102, the conventional computer system 100 includes a first server 106 coupled to a first disk drive 108 by a first fibre channel network 110. The first server 106 is also coupled to a tape drive 112 using a Small Computer System Interface (“SCSI”) bus 114. The first disk drive 108 operates to store data 116 that may be transferred for archival or backup purposes to the tape drive 112 by way of the first backup data path 102. More specifically, the data 116 traverses the first backup data path 102 by utilizing the first disk drive 108, the first fibre channel network 110, the first server 106 and the SCSI bus 114 before arriving at the tape drive 112. On the other hand, the tape drive 112 may include data 117 (e.g., backup data) that can be moved or restored to the first disk drive 108 by way of the first backup data path 102.
In describing the components associated with the second data path 104, the conventional computer system 100 includes a system network 118 (e.g., Local Area Network (“LAN”)) for coupling a second server 120 to the first server 106. A second fibre channel network 122 connects the second server 120 to a second disk drive 124. The second disk drive 124 stores data 126 capable of being transferred via the second backup data path 104 to the tape drive 112. More specifically, the data 126 traverses the second backup data path 104 by utilizing the second disk drive 124, the second fibre channel network 122, the second server 120, the system network 118, the first server 106 and the SCSI bus 114 prior to arriving at the tape drive 112. Likewise, the data 117 located in the tape drive 112 may be moved or restored to the second disk drive 124 by way of the second backup data path 104.
Unfortunately, the routing of data 116, 117 or 126 through either of the two backup data paths 102 or 104 includes moving the data through at least one of the servers 106 and 120. The moving of data 116, 117 or 126 through any of the servers 106 and 120 is problematic, because, each server has a limited memory bandwidth and a limited Input/Output capacity which can lead to a bottleneck for the passing data 116 or 126. Any bottlenecks will obviously degrade the performance of the conventional computer system 100.
Moreover, the routing of data 126 or 117 through the system network 118 using the second backup data path 104 is also problematic, because, the system network also has a limited bandwidth which can lead to another potential bottleneck for the passing data 126. To overcome the potential bottleneck associated with the system network 118, a second conventional computer system 150 has been developed to include a third backup data path 152 that will be discussed with reference to FIG. 1B.
Referring to FIG. 1B, there is illustrated the second conventional computer system 150 including a storage management scheme having the third backup data path 152. In describing the components associated with the third backup data path 152, the second conventional computer system 150 includes a third server 154 coupled to a third disk drive 156 (e.g., library of disk drives) and a tape drive 158 via a storage area network 160 (e.g., fibre channel network). Generally, the third disk drive 156 operates to store data 162 that may be transferred to the tape drive 158 by way of the third backup data path 152, where the data traverses not only the third server 154 but the storage area network 160 (twice) prior to reaching the tape drive. However, the data 162 is still transferred through the third server 154 which has the same bottleneck problem discussed earlier with reference to the first and second servers 106 and 120 of FIG. 1A.
Accordingly, there is a need for a computer system and method using an intelligent controller and storage area network for routing data between peer-level storage units while bypassing a server or workstation. There is also a need to free the server from moving data through its memory and interconnects during backup or archival procedures. These and other needs are satisfied by the computer system and storage management method of the present invention.